PRIOR ART
The invention concerns a firearm, in particular a hand firearm with a bolt carriage borne in a displaceable fashion in a weapon housing for motion, in or in opposition to, the firing direction between stops for the front firing position and the rear open position, with a barrel borne in an axially displaceable fashion in an opening at one radial side of the bolt carriage, the bolt carriage having an impact surface serving as a stop for the back end of the barrel, and with a guide rod borne at its front end section substantially parallel to the barrel in a guide opening of a yoke member disposed for formed fitting displacement with the bolt carriage and is connected at its rear side with the barrel via a carrier coupling allowing displacement play, and with an advancing spring (closing spring) which engages at its front end, the bolt carriage and, at its other end, the housing in the vicinity of the rear end section of the guide rod and with a locking mechanism which locks the barrel and the bolt carriage with respect to each other in a displacement direction in the front firing position and which unlocks them after the bullet leaves the barrel after a certain common recoil displacement in a direction opposite to the shooting direction in consequence of which the bolt carriage continues toward the open position whereas the path of the barrel is stopped by an abutment. Such firearms have a locked bolt and release the locking shortly after firing the bullet and after the shot has left the barrel and the bolt carriage, including the barrel, have recoiled along a certain length. After unlocking, the barrel travel is stopped by an abutment, whereas the bolt carriage continues along its path into the opened position. The empty cartridge is thereby expelled and a new cartridge having a bullet and a charge slips into the cartridge bearing provided in the rear end of the barrel due to the separation between the cartridge bearing and the impact surface resulting during the forward motion of the bolt carriage. After the bolt carriage returns to the firing position, the bolt carriage carries the barrel via its impact surface along with it into the forward firing position, wherein the barrel is once more locked to the bolt carriage. This construction has prevailed in particular with larger cartridges having high caliber e.g. 9 mm parabellum, since such a locked bolt structure facilitates a bolt carriage of substantially reduced weight. and also provides a maximum amount of safety for the rifleman.
In a conventional firearm (Colt-Browning system) mutually engaging grooves and protrusions are disposed on the upper side of the barrel and in the opposing inner side of the bolt carriage which snap into each other in the locked position. After the shot has been fired and after recoil along a certain length, a chain link member pulls the end of the barrel in a downward direction for unlocking. The link cooperates with a stationary transverse bolt which simultaneously serves as a stop. This type of construction with which the barrel, during its motion in the backward direction, is simultaneously pulled downwardly, requires an appropriate amount of play in guiding the barrel (also at its front portion) leading to a reduced accuracy which increases with use. The link motion of the barrel dictated by this structure can only assure firing precision when particular types of ammunition are used and not with other types of ammunition often preferred by the riflemen.
In another conventional firearm in accordance with the precharacterized part of the main claim (DE PS 43 41 131), the back section of the barrel has a reinforcement in the vicinity of the cartridge bearing which forms a shoulder cooperating with an opening in the bolt carriage in such a fashion that when firing, the barrel is firmly locked to the bolt and after the bullet has left the barrel, the barrel must be pivoted in a downward direction at its back end for unlocking, wherein the reinforcement moves through the opening to allow the bolt carriage to glide past this clearance. This unlocking motion is achieved by a link disposed below the barrel which, after recoil along a certain length, cooperates with a corresponding opposing member disposed in the housing in such a fashion that the back portion of barrel is pulled in a downward direction and unlocked during the additional common motion of the bolt carriage and barrel.
The mutually facing transverse surfaces on the bolt carriage and the barrel which serve for locking are relatively small in this conventional firearm so that a substantial degree of surface loading occurs after the shot has been fired. This is particularly disadvantageous, since the bolt carriage material and in particular that of the barrel is relatively soft, which could lead to distortions, jamming, and to increased play.
Particularly in the original Colt-Browning system)the slanted barrel leads to an increased torque acting on the weapon during firing due to the increased separation between the force vectors of the cartridge and the hand of the rifleman, resulting in a stronger upward recoil of the weapon. Particularly when a plurality of bullets are sequentially fired, a time consuming reaiming is thereby necessary.
The slanted pivoting of the barrel also disadvantageously necessitates a minimal separation between the barrel axis and the guide rod axis so that the triggering device must also have a point of rotation or a finger grip position which is relatively far from the axis of the barrel. This is disadvantageous during firing due to the resulting lever arm relationships.